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The advanced tendencies in building materials development are related to the design of cement composites with a reduced amount of Portland cement, contributing to reduced CO2 emissions, sustainable development of used non-renewal raw materials, and decreased energy consumption. This work deals with water cured for 28 and 120 days cement composites: Sample A—reference (white Portland cement + sand + water), Sample B—white Portland cement + marble powder + water, and Sample C white Portland cement + marble powder + polycarboxylate-based water reducer + water. By powder X-ray diffraction and FTIR spectroscopy, the redistribution of CO32−, SO42−, SiO44−, AlO45−, and OH− (as O-H bond in structural OH− anions and O-H bond belonging to crystal bonded water molecules) from raw minerals to newly formed minerals have been studied, and the scheme of samples hydration has been defined. By thermal analysis, the ranges of the sample’s decomposition mechanisms were distinct: dehydration, dehydroxylation, decarbonation, and desulphuration. Using mass spectroscopic analysis of evolving gases during thermal analysis, the reaction mechanism of samples thermal decomposition has been determined. These results have both practical (architecture and construction) and fundamental (study of archaeological artifacts as ancient mortars) applications.

In this work, the influence of halloysite nanotubes (HNTs) on the mechanical and thermal properties of the poly(lactic acid)/polypropylene carbonate (PLA/PPC 70/30) blend was studied. The HNT was incorporated into the PLA/PPC blend by melt mixing. It was found that addition of 2-6 wt % HNT successfully improved the tensile and flexural strength as well as the flexural and Young’s moduli of PLA/PPC blend, due to the reinforcing effect. Although the elongation at break decreases with increasing HNT content, its value is much higher than that of pure PLA. Moreover, the addition of HNT didnot affect the miscibility of PLA and PPC, since two glass transition temperatures were observed in the DSC thermograms. However, a higher content of HNT may improve the compatibility between PLA and PPC as evidenced by the lower difference between the glass transition temperature of PPC and PLA and reduced crystallinity resulting in higher tensile strength of nanocomposites.Keywords: PLA, PPC, HNT, mechanical properties, thermal properties.

Bio-ingredients (animal urine and honey) assisted synthesis of Fe doped ZnO nanostructures has been reported. The structural, optical, morphological, and thermal properties of Fe–ZnO nanostructures were investigated using XRD, FTIR, FESEM, TEM, and TGA. The average crystallite size of Fe–ZnO nanostructures made with animal urine is 34.2 nm, while those made with honey have an average crystallite size of 8.8 nm. It indicates that the size of Fe–ZnO nanostructure crystallites was determined in part by reaction time. FESEM was used to verify the nanostructures of the spherical shaped nanoparticles, and the honey Fe–ZnO sample showed a uniform distribution of particles. EDX analysis confirmed the existence of Zinc (Zn), Iron (Fe), and Oxygen (O) in the synthesized sample. According to TEM photos of Fe–ZnO nanostructures, the particle size of the samples is well correlated with the crystallite size determined by XRD. The thermal stability of Fe–ZnO nanostructures, as well as the effect of these natural ingredients on thermal stability, has been investigated. The surface charge and Zeta potential value of Fe doped ZnO nanoparticles using honey and Animal urine have been analyzed. The obtained values confirm the honey used Fe–ZnO nanoparticles has higher stability (−22.7 mV) than the animal urine assisted sample (−10.1 mV).

The title compounds were prepared via a wet chemistry route and their crystal structures were determined from single crystal X-ray diffraction data. Na2Mn(SO4)2·4H2O crystallizes with a monoclinic symmetry, space group P21/c, with a = 5.5415(2), b = 8.3447(3), c = 11.2281(3) Å, β = 100.172(1)°, V = 511.05(3) Å3 and Z = 2. Na2Ni(SO4)2·10H2O also crystallizes with a monoclinic symmetry, space group P21/c, with a = 12.5050(8), b = 6.4812(4), c = 10.0210(6) Å, β = 106.138(2)°, V = 780.17(8) Å3 and Z = 2. Na2Mn(SO4)2·4H2O is a new member of the blödite family of compounds, whereas Na2Ni(SO4)2·10H2O is isostructural with Na2Mg(SO4)2·10H2O. The structure of Na2Mn(SO4)2·4H2O is built up of [Mn(SO4)2(H2O)4]2− building blocks connected through moderate O–H⋯O hydrogen bonds with the sodium atoms occupying the large tunnels along the a axis and the manganese atom lying on an inversion center, whereas the structure of Na2Ni(SO4)2·10H2O is built up of [Ni(H2O)6]2+ and [Na2(SO4)2(H2O)4]2− layers. These layers which are parallel to the (100) plane are interconnected through moderate O–H⋯O hydrogen bonds. The thermal gravimetric- and the powder X-ray diffraction-analyzes showed that only the nickel phase was almost pure. At a temperature above 300 °C, all the water molecules evaporated and a structural phase transition from P21/c-Na2Ni(SO4)2·10H2O to C2/c-Na2Ni(SO4)2 was observed. C2/c-Na2Ni(SO4)2 is thermally more stable than Na2Fe(SO4)2 and therefore it would be suitable as the positive electrode for sodium ion batteries if a stable electrolyte at high voltage is developed. Other information Published in: RSC Advances License: https://creativecommons.org/licenses/by-nc/3.0 See article on publisher's website: http://dx.doi.org/10.1039/d0ra00301h

The present study replaced 3.30 and 9.00 mol.% BaO for CaO in a SiO2–B2O3–Al2O3–CaO–Na2O–P2O5 bioactive glass system used for implant coating applications. Variations of the glass structure, thermal properties, cytotoxicity, and radiopacity of glasses were studied. As demonstrated by the results, upon adding barium oxide to the glass structure, the weight density increased significantly, while a slight decrease in oxygen density was determined. Introducing barium oxide into glass composition did not cause any considerable change in the spectra of FTIR and Raman. It was demonstrated that the amount of bridging oxygen in the glass structure remained quite unaffected. The hot stage microscopy evaluations revealed further shrinkage of barium-containing frits due to lower viscosity and hence, higher viscous flow of these glasses. By substituting barium oxide for calcium oxide and increasing its concentration, the glass transition temperature (Tg) and the dilatometric softening temperature (Td) decreased, while the thermal expansion coefficient increased. Moreover, upon substituting 9 mol.% barium oxide for calcium oxide, a 30 °C reduction in maximum sintering temperature (Tms) of the glass was obtained, whereas the shrinkage rate was increased 1.7 times. It was indicated that the sintering process of barium-incorporated glasses would easily proceed without any phase crystallization. The barium-incorporated glasses exhibited more radiopacity. Additionally, no cytotoxic effect was caused by the substitution, and the Ba-containing glasses could be used for biomedical applications and implant coating as well.

The effects of heat treatment at various temperatures on mechanically separated bamboo fibers and parenchyma cells were examined in terms of color, microstructure, chemical composition, crystallinity, and thermal properties. The heat-treated parenchyma cells and fibers were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), chemical composition analysis, and thermogravimetric analysis (TGA). The results revealed that the colors of bamboo fibers and parenchyma cells were darkened as treatment temperature increased. The microstructure of the treated fibers and parenchyma cells slightly changed, yet the shape of starch granules in parenchyma cells markedly altered at a temperature of above 160 °C. The chemical compositions varied depending on the heat treatment temperature. When treated at 220 °C, the cellulose content was almost unchanged in fibers but increased by 15% in parenchyma cells; the hemicellulose content decreased and the lignin content increased regardless of fibers and parenchyma cells. The cellulose crystal structure was nearly unaffected by heat treatment, but the cellulose crystallinity of fibers changed more pronouncedly than that of parenchyma cells. The thermal stability of parenchyma cells after heat treatment was affected more substantially compared to fibers.

Free-standing thin films of polyaniline (PANI) with polyvinyl chloride (PVC) were synthesized and studied for variations in the structural, optical, and thermal properties with changing polyaniline concentration in the composites. Fourier transform infrared spectra show interactions between polymeric entities. XRD shows an increase in peak intensities with polyaniline with an exception at 50% polyaniline content. SEM micrographs verify the morphological changes of the composites. The reduction in chain length of composites with increased concentration of PANI is supported by the shift in absorption edge of UV-VIS spectra towards longer wavelengths. A reduction in direct and indirect band gaps and Urbach’s energy with increasing PANI concentration was observed. A monotonic increase in the intensity of photoluminescence with PANI concentration was observed with an exception for 40% polyaniline content. The glass transition temperature (Tg) for PANI/PVC composites showed a slow reduction with increased PANI concentration.

To modify the thermal properties of pitch by adding polyvinyl chloride (PVC), co-pyrolysis of PVC and coal tar pitch was performed. PVC decomposes into HCl and de-HCl PVC (polyene) above 200 °C, and these substances affect the synthesis behavior of coal tar pitch. It was confirmed that HCl induces cracking, promotes the radical reaction and lowers the polycondensation initiation temperature of coal tar pitch. Furthermore, aromatic components produced by the cyclization reaction of polyene participate in the polycondensation reaction, which increases the molecular weight of the pitch. This leads to an increase in softening point and coking value of pitch. The related mechanisms were assessed using thermal analysis (TGA, DTG, DSC) and molecular weight distribution analysis (MALDI-TOF).

Welan is a branched polymer in the gellan family of polysaccharides. It has good compatibility with divalent calcium ions with a potential use in cementing applications. It is also been utilized as an anti-washout material for underwater concrete placement. Herein, influence of divalent cations Ca2+, Ni2+, Mg2+, Zn2+ and Sr2+ on the gelling and thermal properties of welan have been investigated. The viscoelastic properties reveal strong gelation behavior that are stable up to 80 °C. Among all the five cations Ni2+, Ca2+, Zn2+ and Sr2+ are suited well, compared to Mg2+ ions, to promote favorable interactions among the welan chains leading to stronger junction zones and elastic moduli. The melting peak and enthalpy are dependent on the nature and size of the divalent cation. The outcome is deemed to aid to expand the welan utility in food and non-food applications.

This work presents the synthesis, structural investigation, and some properties of a new PLA-Siloxane-PEO hybrid featuring covalent bonds between polymers and siloxane nodes. The synthesis simultaneously connecting PLA and PEO chains directly to the inorganic phase is first achieved through the use of sol–gel process. The structural features, thermal properties and chemical stability of this biocompatible system have been studied by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, 29Si Nuclear Magnetic Resonance (NMR), scanning electron microscopy (MEV), X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). SEM and SAXS measurements showed that the siloxane nodes act as crosslinks between the polymer chains promoting high miscibility between PLA and PEO. FTIR, Raman XRD, DSC, and TGA showed that the presence of the siloxane nodes diminishes the crystallinity of both polymers and increases their thermal resistance. In addition to the absence of brittleness due to the low crystalline character of PLA, this new material exhibits a fantastic resistance to PLA degradation in aqueous medium, attributed both to the presence of the siloxane particles acting as a barrier towards water diffusion and to the hydrophilic PEO segments which may attract water molecules, preventing PLA hydrolysis. All of these characteristics offer an amazing perspective for the use of this hybrid material in biological, medical, and pharmaceutical applications.

In recent years, because of their excellent electrocatalytic action and applications in different fields, metal oxide nanostructures have received massive consideration from scientists. Zinc oxide nanostructures are useful materials for a range of sensing applications and possess admirable electrocatalytic properties and stability. The current research presents the natural citric acid assisted synthesis of ZnO nanostructures and their structural, optical, morphological and thermal properties. X-ray diffraction was studied for the phase assessment of as prepared (Z1) and annealed ZnO (Z2) nanostructures and the crystallite sizes of the Z1 and Z2 samples were also located in the range between 35 nm and 38 nm. FESEM and TEM experiments were carried out to explore the surface features of Z1 and Z2 samples. The polycrystalline existence of the samples is demonstrated by the hexagonal, cubic and spherical shaped ZnO nanostructures. The energy band gap of Z1 and Z2 samples was determined (3.16 eV for Z1 and 3.12 eV for Z2) from the UV spectrum. The impact of annealing treatment on the thermal stability of ZnO nanostructures was studied and the main peak was observed for the Z1 sample at ~249 °C and for the Z2 sample at ~289 °C.

Co0.91Ni0.09Sb3 embedded with Cu nanoparticles (NPs) was synthesized by applying a hydrothermal process followed by spark plasma sintering. The effects of Cu NPs on the electrical and thermal transport properties of the Co0.91Ni0.09Sb3 matrix were investigated in the temperature range of 303–773 K. Cu NPs introduced into the Co0.91Ni0.09Sb3 matrix slightly decreased the electrical conductivity and significantly enhanced the Seebeck coefficient by the energy filtering effect, leading to an improved power factor at 773 K. Furthermore, a significant decrease in the thermal conductivity was realized by increasing the number of grain boundaries. These favorable effects contributed to the improvement in ZT to a value ~57% higher than that of pristine Co0.91Ni0.09Sb3. The highest ZT value of 1.02 was achieved by incorporating 4.5 wt% of Cu NPs in Co0.91Ni0.09Sb3 at 773 K. Thus, decoupling the electrical and thermal transport properties of thermoelectric materials is a viable strategy for optimizing the ZT value.

Recently, with the progress of research in amending and developing the properties of inorganic materials, researchers have become focused on using inexpensive and environmentally friendly materials such as organic materials from natural sources that have proven effective in improving the properties of materials in various applications. In recent years, melanin has become an attractive topic for researchers due to its distinctive structural properties that have been distinguished in various application fields. Here, we report the use of ultrasonication under UV radiation for synthesis. The influence of natural melanin on the structural, optical and thermal properties of TiO2 nanoparticles was investigated by using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and UV–Vis spectroscopy. It was observed that incorporating natural melanin on TiO2 nanoparticles (TiO2-Mel) occurred at approximately 2.01 eV with low value of Urbach energy around 100 meV indicates improvement in crystalline structure. Thermal results showed that TiO2-Mel is stable even with temperatures up to 400°C. According to the results obtained by the thermal stability of melanin with titanium dioxide can makes it a good candidate in many application such as solar cells and optoelectronic that require optical efficiency and thermal stability for long periods.

The multiple eutectic nitrates with a low melting point are widely used in the field of solar thermal utilization due to their good thermophysical properties. The addition of nanoparticles can improve the heat transfer and heat storage performance of nitrate. This article explored the effect of MgO nanoparticles on the thermal properties of ternary eutectic nitrates. As a result of the decomposition reaction of the Mg(OH)2 precursor at high temperature, MgO nanoparticles were synthesized in situ in the LiNO3–NaNO3–KNO3 ternary eutectic nitrate system. XRD and Raman results showed that MgO nanoparticles were successfully synthesized in situ in the ternary nitrate system. SEM and EDS results showed no obvious agglomeration. The specific heat capacity of the modified salt is significantly increased. When the content of MgO nanoparticles is 2 wt %, the specific heat of the modified salt in the solid phase and the specific heat in the liquid phase increased by 51.54% and 44.50%, respectively. The heat transfer performance of the modified salt is also significantly improved. When the content of MgO nanoparticles is 5 wt %, the thermal diffusion coefficient of the modified salt is increased by 39.3%. This study also discussed the enhancement mechanism of the specific heat capacity of the molten salt by the nanoparticles mainly due to the higher specific surface energy of MgO and the semi-solid layer that formed between the MgO nanoparticles and the molten salt.

The current system of disposal of plastic materials fabricated from petroleum‐based resources causes serious environmental pollution. To solve the problem, a bioplastic called “cell‐plastic” is developed, in which unicellular green algal cells serve as a fundamental resource. This approach converts CO2 in the atmosphere directly into plastic products by exploiting the photosynthetic‐driven proliferation of algal cells. Herein, cell‐plastic films are fabricated using biodegradable and water‐soluble polyvinyl alcohol (PVA) as a matrix, in which the effects of a cell‐to‐matrix mixing ratio and the chemical structure of the matrix on the mechanical and thermal properties are investigated. As a method of the chemical structural change, a cross‐linking structure is introduced to the matrix by connecting hydroxy groups of PVA using aldehyde. The tensile tests reveal that the PVA‐cell‐plastic film maintains the mechanical properties of PVA film. Moreover, a cross‐linked cell‐plastic film exhibits high water absorption, making it suitable as a functional cell‐plastic material., Given the goal of reducing CO2 emissions and plastics pollution, a method to produce “cell‐plastics” is developed, whereby unicellular green algal cell serves as a raw material. In this research, polyvinyl alcohol (PVA) with biodegradability is used as a matrix to fabricate cell‐plastics with high mechanical strength. Moreover, cross‐linked PVA produces a functional cell‐plastic with high water‐retention.

This article aimed to study the effects of chitosan fiber and a newly modifying agent, based on organosolv lignin, on mechanical and thermal performances and the enzymatic degradation of PLA/chitosan biocomposites. A newly modifying agent based on polyacrylic acid-grafted organosolv lignin (PAA-g-OSL) was synthesized via free radical copolymerization using t-butyl peroxide as the initiator. The biocomposites were prepared using an internal mixer and the hot-pressed method at various fiber loadings. The results demonstrate that the addition of chitosan fiber into PLA biocomposites remarkably decreases tensile strength and elongation at break. However, it improves the Young’s modulus. The modified biocomposites clearly demonstrat an improvement in tensile strength by approximately 20%, with respect to the unmodified ones, upon the presence of PAA-g-OSL. Moreover, the thermal stability of the modified biocomposites was enhanced significantly, indicating the effectiveness of the thermal protective barrier of the lignin’s aromatic structure belonging to the modifying agent during pyrolysis. In addition, a slower biodegradation rate was exhibited by the modified biocomposites, relative to the unmodified ones, that confirms the positive effects of their improved interfacial interaction, resulting in a decreased area that was degraded through enzyme hydrolysis.

Herein, bio-based alginate (Alg) containing-metal atom beads (M= Cu and Ce) were synthesized via an alginate cross-linking method, and studied using experimental techniques combined with theoretical simulations. Firstly, FTIR, TGA and SEM analyses were carried out to study the cross-linking structural features,, thermal stability, and surface morphology. Besides, density functional theory (DFT) methods were used to calculate global reactivity parameters such as HOMO-LUMO energy gaps (ΔEH-L), electronegativity (μ), hardness (η), and electrophilic and nucleophilic indicators using both gas and aqueous media ; the latter for the study of the complexation process. Results showed that Alg@Ce and Alg@Cu beads behave differently and as a function of the increasing temperature. This behaviour c was also predicted by the energy conformer differences between Alg@Ce and Alg@Cu, which were found out theoretically and explained with the combined study of the vibrational modes between the carboxylate group with either Cu or Ce. Overall, the reactivity of the Alg@Ce bead was higher than that of the Alg@Cu counterpart; results could be used as a cornerstone to transfer the materials here studied to a wider range of applications.

Coking is a major challenge in steam reforming of oxygenated organics, especially the ones in bio-oil with multiple oxygen-containing functionalities. The property of the resulting coke is believed to relate with structures of the organics. In this study, steam reforming of xylose, xylitol and furfural, which are representatives of sugars, alcohols of multiple hydroxyl groups, and furans, were performed to correlate molecular structure and property of coke. The results showed that xylose polymerized rapidly during the steam reforming, forming initially π-conjugated polymeric organics and substantial amount of coke that was amorphous, aliphatic, thermally unstable with abundant olefin C = C and –OH. In comparison, steam reforming of xylitol generated little coke, as xylitol contains no C = O that was the primary reason for the serious coking in xylose reforming. Steam reforming of furfural also generated large amount of coke that was mainly aromatic with high thermal stability and high resistance towards oxidation, due to the reserve of the furan ring-like structure in the coke. Functionalities of the reactants dictated the thermal properties of the coke and also their morphologies. The amorphous coke formed in xylose reforming was bubble-like, while the coke in furfural reforming mainly included carbon nanofiber of rugged surface and carbon nanotubes of thick wall. The multiple hydroxyl groups in xylitol, however, resulted in the coke of carbon nanotube form with large inner diameters.

The purpose of this systematic literature review (SLR) study is to assess the importance of thermal properties and the depth of analysis on Polyvinyl alcohol (PVA) -based hydrogel. Google Scholar is used as a search for database sources using Publish or Perish software, which is related to PVA-based hydrogel’s thermal properties from 2018 to 2020. Thermal properties are focused on the DSC thermogram characteristic. These results strongly indicate that PVA-based hydrogel’s thermal properties are very important and considered for their potential application.

The “graft onto” method is used to obtain the “stimuli-responsive water-soluble polymer” with low concentration, where 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and n-hydroxysulfosuccinimide sodium salt as catalyst and sodium polyacrylate as backbone chain. The molecular structure of the polymer is characterized by Nuclear Magnetic Resonance (1H NMR). The influence of temperature on polymer rheological properties and aggregation is studied by rheometer and fluorescence probe respectively. The results show that when the polymer concentration is higher than 1500 mg/L, the thickening properties can be controlled by diacetoneacrylamide, thermal-responsive monomer, NaCl and polymer concentration, where the apparent viscositymax/ viscositymin (ηmax/ηmin) changes from 18.3 to 39.4, from 2.6 to 45.5, from 9.3 to 36, from 7.8 to 36.9 respectively and the lower critical solution temperature (LCST) changes from 60 °C to 40 °C. The reason for the polymer with controllable thickening properties is that the thermal-responsive monomers change from hydrophilicity to hydrophobicity, thus forming aggregations. At this time, the polymer chains form network structures. Because of controllable thickening properties at low concentration, it has potential application prospects.

To achieve high heat storage capacity, excellent mechanical, optical and thermal properties in calcium looping thermochemical heat storage, the novel SiC/Mn co-doped CaO pellets were fabricated by the extrusion-spheronization method. The heat storage performances of the novel CaO pellets were studied under harsh calcination (pure CO2, 950 °C) and pressurized carbonation (pure CO2, 13 bar, 800 °C) conditions in a dual fixed-bed reactor system. The additions of SiC and Mn enhance the cyclic stability of CaO pellets during the multiple heat storage cycles. When the mass ratio of CaO:SiC:MnO2 is 100:5:5, the co-doped CaO pellets exhibit an excellent heat storage performance. The effective conversion and heat storage density of the co-doped CaO pellets are 41.5% higher than those of original CaO pellets, respectively. Meanwhile, the co-doped CaO pellets possess a good optical absorption capacity and a high thermal conductivity, which are 17.6 and 3.2 times as high as those of original CaO pellets, respectively. In addition, the co-doped CaO pellets show much higher crushing strength and lower weight loss during the attrition test. The stronger interaction between SiC and CaO cluster mitigates the movement of CaO, which is determined by density functional theory simulation. The adsorption of CO2 onto the CaO surface is enhanced by the addition of Mn. Therefore, SiC/Mn co-doped CaO pellets used in the calcium looping thermochemical heat storage process appear promising.

In this work, we aimed to determine the role of the mechanical, structural, and thermal properties of poly(l-lactide-co-glycolide-co-trimethylene carbonate) (P(l-LA:GA:TMC)) with shape memory in the formulation of implantable and biodegradable rods with aripiprazole (ARP). Hot melt extrusion (HME) and electron beam (EB) irradiation were applied in the formulation process of blank rods and rods with ARP. Rod degradation was carried out in a PBS solution. HPLC, NMR, DSC, compression and tensile tests, molecular weight (Mn), water uptake (WU), and weight loss (WL) analyses, and SEM were used in this study. HME and EB irradiation did not influence the structure of ARP. The mechanical tests indicated that the rods may be safely implanted using a pre-filled syringe. During degradation, no unfavorable changes in terpolymer content were observed. A decrease in the glass transition temperature and the Mn, and an increase in the WU and the WL were revealed. The loading of ARP and EB irradiation induced earlier pore formation and more intense WU and WL changes. ARP was released in a tri-phasic model with the lag phase, therefore, the proposed formulation may be administered as a delayed-release system. EB irradiation was found to accelerate ARP release.

In this work, the epoxidized castor oil (ECO) with self-crosslinking structure is prepared and a series of PLA/ECO blends are fabricated via dynamic vulcanization. The effects of raw castor oil and ECO with different contents on the static and dynamic mechanical properties, rheological properties, crystalline properties were studied. FTIR NMR and GPC results indicate the generation of self-crosslinking structure and the interaction between the oil and PLA matrix. DSC and TGA results show a higher crystallinity and lower thermal stability for PLA/ECO blends. It is also shown the better rheological and dynamic mechanical properties are obtained in PLA/ECO blends in comparison with raw castor oil filled samples. The data of static mechanical properties exhibit that ECO leads a much better toughening effect than that of the raw castor oil, which is also proved by the morphology photos of SEM, showing a better dispersion and smaller droplet size of oil, as well as the toughening mechanism of shear yielding and internal cavitation in PLA. However, the structures are defected in PLA matrix with the ECO contents over 10 wt% due to the agglomeration of ECO in local areas, leading significant decrease in mechanical properties.

In the present work, dapsone-capped TiO2 nanoparticles (DAP-TiO2-NPs) were successfully prepared as a decorated bio-agent for enhancing the properties of the biodegradable polyvinyl alcohol (PVA) nanocomposites. The structure of synthesized TiO2-NPs was characterized by X-ray diffraction (XRD). The fabricated biodegradable films were subjected to variable tests like SEM analysis, UV–vis spectroscopy, mechanical properties, thermogravimetric analysis (TGA), as well as antibacterial activity. The SEM images showed that the capping dapsone into the surface of TiO2-NPs improved the dispersion degree and miscibility of DAP inside the PVA matrix, especially at 0.1 % filler content. The obtained results from UV–vis exhibited that all fabricated films based on DAP-TiO2-NPs possessed superb UV-shielding properties even at lower nanofiller ratios, blocking nearly all three bands of UV lights, and up 98 % of visible light as well, irrespective to neat PVA or PVA/DAP blend. Withal, UV–vis reflectance was revealed that the reflectivity of filled films was changed in the visible range with increasing UV exposure time, indicating the color change in the film within a few minutes. These data were confirmed by chromaticity co-ordinates calculations. Also, the tensile properties, thermal stability, and antibacterial activity of nanocomposite films were remarkably improved. This study points out that a new utilization for PVA/DAP-TiO2 nanocomposite films in promising applications such as food-safe packaging and UV-blocking biomedical areas.

The effects of magnesium salts with various anion species on the structure and properties of a poly(vinyl alcohol) (PVA) film were studied. The glass transition temperature of the PVA film increased following the addition of a magnesium salt. Furthermore, the salt greatly enhanced the modulus and yield stress and reduced the crystallinity of the film. These effects were attributed to the strong ion–dipole interactions between the magnesium salts and the PVA chains. The strength of interaction, i.e., the reduction of segmental motions, depended on the anion species in the following order: Mg(ClO4)2, MgBr2, MgCl2, Mg(CH3COO)2, and MgSO4. The order corresponded to the Hofmeister series, which predicts the ability to break the structure of water.

This study investigates the effects of four multifunctional chain-extending cross-linkers (CECL) on the processability, mechanical performance, and structure of polybutylene adipate tereph-thalate (PBAT) and polylactic acid (PLA) blends produced using film blowing technology. The newly developed reference compound (M·VERA® B5029) and the CECL modified blends are characterized with respect to the initial properties and the corresponding properties after aging at 50◦ C for 1 and 2 months. The tensile strength, seal strength, and melt volume rate (MVR) are markedly changed after thermal aging, whereas the storage modulus, elongation at the break, and tear resistance remain constant. The degradation of the polymer chains and crosslinking with increased and decreased MVR, respectively, is examined thoroughly with differential scanning calorimetry (DSC), with the results indicating that the CECL-modified blends do not generally endure thermo-oxidation over time. Further, DSC measurements of 25 µm and 100 µm films reveal that film blowing pronouncedly changes the structures of the compounds. These findings are also confirmed by dynamic mechanical analysis, with the conclusion that tris(2,4-di-tert-butylphenyl)phosphite barely affects the glass transition temperature, while with the other changes in CECL are seen. Cross-linking is found for aromatic polycarbodiimide and poly(4,4-dicyclohexylmethanecarbodiimide) CECL after melt-ing of granules and films, although overall the most synergetic effect of the CECL is shown by 1,3-phenylenebisoxazoline. © 2021 by the authors. Licensee MDPI, Basel, Switzerland., Ministry of Education, Youth, and Sports of the Czech Republic-DKRVO [RP/CPS/2020/003], RP/CPS/2020/003; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT

Emulsions are thermodynamically unstable systems that, by incorporating more components in their formulation, increase their complexity and make their study challenging. However, a good selection of compounds in the formulation, and suitable methods for their preparation, could result in systems with favorable thermomechanical and microstructural properties for multiple applications. The objective of this research was to evaluate the influence of temperature, time, and surfactant concentration on the microstructural, thermodynamic, and rheological properties of organogel emulsions, and to present in a simple way the relationship between enthalpy of fusion and rheological properties (i.e., viscosity) in organogel emulsions W/O. Canola oil, monoglycerides and polyglyceryl polyricinoleate (PGPR) were used as the oil phase. Microscopy, DSC, and Creep-recovery tests were performed. A molecular organization phenomenon was observed that resulted in systems with a more dispersed and ordered microstructure, delaying the phase separation for 28 days of evaluation. In addition, an increase in the internal viscosity of the organogel emulsions was reflected in higher enthalpy of fusion values at 10 °C. An inverse behavior was also presented in emulsions at 25 °C. The combined activity of stabilizing agents, as well as the three-dimensional network formed in continuous phase, avoided phenomena of coalescence and phase separation by keeping distant the drops of water and the oily liquid phase, while leading to a better organized microstructure over time and retaining good rheological properties.

With the increase in the speed of various aircraft and the demand for lightweight weapons and equipment, the demand for high-performance, high-temperature-resistant resin-based composite materials has become more urgent. The temperature resistance and molding process of composite materials are determined by the temperature resistance and manufacturability of the resin, so there is an urgent need to develop a resin that has both high temperature resistance and excellent process performance. The temperature resistance and processability of the resin are essentially determined by the molecular structure of the resin system. Therefore, in order to design a resin system with excellent heat resistance and processability, the relationship between molecular structure and performance must first be recognized. This paper collects a large amount of experimental data and preliminarily summarizes the influence of different molecular structures on the thermal performance and resin processability of resin polymers from the perspective of structure and performance. This provides a good experience and theoretical basis for the design of high-performance resin systems, providing references and ideas for related research.

The development of biodegradable materials as food packaging material is important not only due to the reduction in environmental pollution but also because of an improvement in the functionality. Rice husk-reinforced biopolymers have offered a possible solution to waste-disposal problems associated with traditional petroleum-derived plastics. Rice husk-reinforced low density polyethylene (LDPE)-based biocomposites have been of great interest for their use as food packaging material. In this work, the LDPE/RH biocomposites with different rice husk (RH) content (10, 20, 30, 40 and 50 wt.%) were prepared by the melt mixing process in a laboratory Brabender mixer. The effect of RH content on the physical, thermal and mechanical properties of LDPE was investigated. More importantly, this work aimed to research the biodegradation of the LDPE/RH biocomposites as well as their effect on ‘Granny Smith’ apples’ respiration. The results showed that the incorporation of RH into the LDPE decreased the thermal stability of LDPE, increased water vapour permeability and water absorption, and increased the degree of crystallinity. The incorporation of RH increased the biodegradability of LDPE as well as the postharvest quality of ‘Granny Smith’ apples. The addition of RH in LDPE film significantly decreased fruit respiration and increased firmness as compared to LDPE film. The composting results showed that after the LDPE/RH biocomposite films were biodegraded for 21 days, the biocomposite films with the highest content of rice husks were the most degraded.

High-molecular-weight poly(butylene 2,4-furanoate) (2,4-PBF), an isomer of well-known poly(butylene 2,5-furanoate) (2,5-PBF), was synthesized through an eco-friendly solvent-free polycondensation process and processed in the form of an amorphous film by compression molding. Molecular characterization was carried out by NMR spectroscopy and GPC analysis, confirming the chemical structure and high polymerization degree. Thermal analyses evidenced a reduction of both glass-to-rubber transition and melting temperatures, as well as a detriment of crystallization capability, for 2,4-PBF with respect to 2,5-PBF. Nevertheless, it was possible to induce crystal phase formation by annealing treatment. Wide-angle X-ray scattering revealed that the crystal lattices developed in the two isomers are distinct from each other. The different isomerism affects also the thermal stability, being 2,4-PBF more thermally inert than 2,5-PBF. Functional properties, such as wettability, mechanical response, and gas barrier capability, were tested on both amorphous and semicrystalline 2,4-PBF films and compared with those of 2,5-PBF. Reduced hydrophilicity was determined for 2,4-isomer, in line with its lower average dipole moment, suggesting better chemical resistance to hydrolysis. Stress–strain tests have evidenced the higher flexibility and toughness of 2,4-PBF with respect to those of 2,5-PBF and the possibility of improving its mechanical resistance by annealing. Finally, the different isomerism deeply affects the gas barrier performance, being the O2- and CO2-transmission rates of 2,4-PBF 50 and 110 times lower, respectively, than those of 2,5-PBF. The gas barrier properties turned out to be outstanding under a dry atmosphere as well as in humid conditions, suggesting the presence of interchain hydrogen bonds. The gas blocking capability decreases after annealing because of the presence of disclination associated with the formation of crystals., Poly(butylene 2,4-furanoate) was obtained from 2,4-isomer of biobased furandicarboxylic acid, and isomerism further improved the key properties for sustainable packaging applications.

Pineapple crown leaf fiber (PCLF) is one of the major biomass wastes from pineapple processing plants. It consists mostly of carbohydrate polymers, such as cellulose, hemicellulose, and lignin. It can be further processed to form a more valuable and widely used nanocrystalline cellulose (NCC). This study investigates the effect of hydrolysis time on the properties of the produced NCC. The acid hydrolysis was conducted using 1 M of sulfuric acid at hydrolysis times of 1–3 h. The resulting NCCs were then characterized by their morphology, functional groups, crystallinity, thermal stability, elemental composition, and production yield. The results show that the NCC products had a rod-like particle structure and possessed a strong cellulose crystalline structure typically found in agricultural fiber-based cellulose. The highest NCC yield was obtained at 79.37% for one hour of hydrolysis. This NCC also displayed a higher decomposition temperature of 176.98 °C. The overall findings suggest that PCLF-derived NCC has attractive properties for a variety of applications.

The present study deals with the formation of a phosphorylated polyvinyl alcohol (PPVA)-Aluminum Phosphate (AlPO4) nanocomposite, changing the pH solution under the two-step process involving the phosphorylation of polyvinyl alcohol (PVA) followed by the conjugation with AlPO4. The composite was formed by varying the pH of the solution in the range of 7–12 and the reflected changes in the product’s morphology, crystallinity, surface nature, thermal stability, etc. were recorded using FESEM, XRD, FTIR, UV-Vis spectroscopy, TGA, etc. From the analysis, it was found that the particles formed with two different sizes of the probed pH, and at pH 10 they were homogeneously distributed. In addition, the morphology of the PPVA-AlPO4 composite also seems to be altered with respect to the pH and this is due to the differences in the amount of H+ and OH− anions. Thus, from the overall analysis, it can be indicated that pH 10 needs to be maintained for the formation of a spherical shape and uniformly distributed PPVA-AlPO4 nanocomposite.

The TiO2 NPs have been successfully synthesized by sol-gel method and the SWCNTs/TiO2 nanostructures have been fabricated by a simple mixing technique. By a solution casting process, pure CMC/PEO and SWCNTs/TiO2 nanohybrid doped CMC/PEO polymer blend films have been prepared. The influence of SWCNTs/TiO2 nanohybrid loading on the thermal, optical, and conductivity properties of the polymer blend has been discussed. The XRD pattern shows that the average crystallite size of the nanoparticles for TiO2 and SWCNTs/TiO2 is 20 nm and 15 nm, respectively, and a change in crystallinity was observed with an increase in doping. The interaction between CMC/PEO chains and SWCNTs/TiO2 nanohybrid is confirmed by FTIR spectra. The optical absorption spectrum shows that the energy gap reduces with the dopant increase. The miscibility between the CMC and PEO was confirmed by DSC thermograms. With an increase in dopant content, the TGA study demonstrates that the system's thermal stability improves. The maximum value of the blend's AC conductivity is 4.77 10−6 S/m, and by increasing the loading of SWCNTs/TiO2 to 3.2 (wt%) increased to 9.23 10−4 S/m. The conduction mechanism changed with SWCNTs/TiO2 loading from the correlated barrier hopping, in the prepared samples. Usage of these nanocomposite films in the semiconductor industry is encouraged by the observed improvements in optical, thermal, and AC conductivity.

Producción Científica, Ultrasonication (US) is a green technology used to physically modify flours to increase their industrial range of applicability. The aim of this work was to study the combined effect that dual US and annealing (ANN) treatments have on starch and protein structure of rice flour, at 20, 40, 50 and 60 °C. Results showed clear modifications of functional, thermal and pasting properties of flours, as well as rheological properties of gels made from them. US+ANN led to generation of small-size particles, which markedly increased the swelling power and starch damage. X-Ray Diffraction and FTIR indicated that starch crystallinity and protein secondary structure was affected by the shear forces of cavitation. The combination of US+ANN improved the crystalline structure arrangement within the starch granules, causing narrowing of the gelatinization temperature range (ΔT). Pasting viscosities were significantly decreased by ultrasonication, following an increasing trend with increasing temperature, while pasting temperature was increased, agreeing in the achievement of a thermodynamically more stable structure. The rheological properties indicated a reduction of the elastic (G') and viscous (G'') moduli after ultrasonication, as well as lower values of tan (), reflecting a higher predominance of elastic modulus versus viscous one than the non-sonicated flours. The rice flour’s properties were found to be highly sensitive to the applied treatment conditions, showing a synergetic effect when sonicating at the highest studied temperature., Ministerio de Economía y Competitividad - Fondo Europeo de Desarrollo Regional (project AGL2015-63849-C2-2-R), Ministerio de Ciencia e Innovación (project PID2019-110809RB-I00), Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (project VA195P20)